Methods and apparatuses for separating liquid particles from a gas-liquid stream

ABSTRACT

A gas-liquid separator comprises a housing having an inlet for receiving a gas-liquid stream and an outlet for discharging a gas stream. An impactor nozzle structure is supported by the housing and situated downstream of the inlet. The impactor nozzle structure receives the gas-liquid stream and accelerates the gas-liquid stream through an orifice that extends through the impactor nozzle structure. An impaction surface is supported by the housing and situated downstream of the orifice. The impaction surface receives the accelerated gas-liquid stream and causes separation of liquid particles from the gas-liquid stream so as to produce the gas stream, and a baffle situated downstream of the impaction surface modifies a flow of the gas stream so as to reduce carryover of liquid particles in the gas stream. A shroud tier an inertial impactor gas-liquid separator is disclosed. A method for separating liquid particles from a gas-liquid stream is disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of and priority to U.S. ProvisionalApplication Ser. No. 61/677,530 filed Jul. 31, 2012, which is herebyincorporated by reference in entirety.

FIELD

The present disclosure relates to gas-liquid separators and methods forseparating liquid panicles from a gas-liquid stream.

BACKGROUND

U.S. Pat. No. 6,290,738, the disclosure of which is hereby incorporatedby reference in its entirety, discloses an inertial gas-liquid separatorhaving a housing with an inlet for receiving a gas-liquid stream, and anoutlet for discharging a gas stream. A nozzle structure in the housinghas a plurality of nozzles receiving the gas-liquid stream from theinlet and accelerating the gas-liquid stream through the nozzles. Aninertial collector in the housing in the path of the acceleratedgas-liquid stream causes a sharp directional change thereof and inpreferred form has a rough porous collection surface causing liquidparticle separation from the gas-liquid stream of smaller size liquidparticles than a smooth non-porous impactor impingement surface andwithout the sharp cut-off size of the latter, to improve overallseparation efficiency including for smaller liquid particles. Varioushousing configurations and geometries are provided.

U.S. Pat. No. 7,614,390, which is hereby incorporated by reference inits entirety, discloses a two stage drainage gas-liquid separatorassembly including an inertial gas-liquid impactor separator having oneor more nozzles accelerating a gas-liquid stream therethrough, and aninertial impactor in the path of the accelerated gas-liquid stream andcausing liquid particle separation from the gas-liquid stream. Theseparator assembly further includes a coalescer filter downstream of theinertial gas-liquid impactor separator and of further liquid particleseparation, and coalescing separated liquid particles.

U.S. Pat. No. 7,473,291, which is hereby incorporated by reference inits entirety, discloses an inertial vas-liquid separator having avariable flow actuator movable to open and close a variable number ofaccelerating flow nozzles.

U.S. Pat. No. 8,075,654, which is hereby incorporated by reference inits entirety, discloses a gas-liquid separator assembly having a flowpassage providing expansion of and reduced flow velocity of thepost-separation gas stream, and in some embodiments provides pre-escaperegions facilitating partial pre-transition of some of the flow.

SUMMARY

This Summary is provided to introduce a selection of concepts that arefurther described below in the Detailed Description. This Summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofthe claimed subject matter.

A gas-liquid separator comprises a housing having an inlet for receivinga gas-liquid stream and an outlet for discharging a gas stream. Animpactor nozzle structure is supported by the housing and situateddownstream of the inlet, the impactor nozzle structure receiving thegas-liquid stream and accelerating the gas-liquid stream through anorifice that extends through the impactor nozzle structure. An impactionsurface is supported by the housing and situated downstream of theorifice, the impaction surface receiving the accelerated gas-liquidstream and causing separation of liquid particles from the gas-liquidstream so as to produce the gas stream. A baffle is situated downstreamof the impaction surface and modifies a flow of the gas stream so as toreduce carryover of liquid particles in the gas stream.

A shroud for an inertial impactor gas-liquid separator separates liquidparticles from a gas-liquid stream by acceleration of the gas-liquidstream through a nozzle and towards an impaction surface so as toproduce a gas stream. The shroud is configured to extend from aperimeter of the impaction surface and has a free end that extendstowards the nozzle. The shroud comprises a plurality of baffles thatcause the gas stream to spiral as the gas stream exits the shroud.

A method for separating liquid particles from a gas-liquid streamcomprises receiving a gas-liquid stream through an inlet of a housingand accelerating the gas-liquid stream through a nozzle and at animpaction surface. The method further comprises causing separation ofliquid particles from the gas-liquid stream so as to produce a gasstream. The method further comprises directing a flow of the gas streamaround an impactor shroud extending from a perimeter of the impactionsurface and having a free end extending towards the nozzle. The methodfurther comprises modifying a flow of the gas stream with a baffle so asto reduce carryover of liquid particles in the gas stream anddischarging the gas stream through an outlet of the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of apparatuses and methods for use with a gas-liquid separatorare described with reference to the following figures. These samenumbers are used throughout the figures to reference like features andlike components.

FIG. 1 illustrates one embodiment of a gas-liquid separator of thepresent disclosure;

FIG. 2 illustrates one embodiment of a baffle according to the presentdisclosure;

FIG. 3 illustrates another embodiment of a baffle according to thepresent disclosure;

FIGS. 4-11 illustrate several other embodiments of baffles according tothe present disclosure;

FIG. 12 illustrates an alternative embodiment of a baffle according tothe present disclosure;

FIG. 13 is a schematic representation of a flow of a gas-liquid streamthrough one embodiment of a gas-liquid separator that does not have abaffle;

FIG. 14 is a schematic representation of a flow of a gas-liquid streamthrough one embodiment of a gas-liquid separator according to thepresent disclosure;

FIG. 15 is a schematic representation of a flow of liquid particles inthe gas-liquid stream, corresponding to the embodiment of FIG. 13;

FIG. 16 is a schematic representation of a flow of liquid particles inthe gas-liquid stream, corresponding to the embodiment of FIG. 14;

FIGS. 17 and 18 illustrate alternative embodiments of a portion of agas-liquid separator of the present disclosure;

FIG. 19 is a schematic representation of a flow of liquid particles in agas-liquid stream according to the embodiments of FIG. 17 or 18;

FIG. 20 illustrates an alternative embodiment of a gas-liquid separatorof the present disclosure; and

FIG. 21 is a schematic representation of a flow of liquid particles in agas-liquid stream according to the embodiment of FIG. 20.

FIG. 22 illustrates one embodiment of a method for separating liquidparticles from a gas-liquid stream.

DETAILED DESCRIPTION

FIG. 1 illustrates a gas-liquid separator 10, such as an air-oilseparator. In the embodiment shown, the gas-liquid separator 10comprises two stages: a first stage 12 comprising a cyclone separatorand a second stage 14 comprising an impactor separator. However, it isto be understood that the present disclosure is not limited to two-stagegas-liquid separators and could be used with various other types ofgas-liquid separators. The gas-liquid separator 10 has a housing 16having an inlet 18 for receiving a gas-liquid stream as shown by arrow20 and an outlet 22 for discharging a gas stream as shown by arrow 24.The gas-liquid separator 10 further comprises an impactor nozzlestructure 26 supported by the housing 16 and situated downstream of theinlet 20. More specifically, in the embodiment shown, the impactornozzle structure 26 is supported between the first stage 12 and thesecond stage 14 of the gas-liquid separator 10. The impactor nozzlestructure 26 receives the gas-liquid stream as shown by arrow 25 andaccelerates the gas-liquid stream through an orifice 28, or a pluralityof orifices 28, that extend through the impactor nozzle structure 26.The gas-liquid separator 10 further comprises an impaction surface 30supported by the housing 16 and situated downstream of the orifice 28.The impaction surface 30 receives the accelerated gas-liquid stream, asshown by arrows 32, and causes separation of liquid particles from thegas-liquid stream so as to produce the gas stream. The gas-liquidseparator 10 further comprises a baffle 8, as will be described furtherherein below, situated downstream of the impaction surface 30 andmodifying a flow of the gas stream, as shown by arrows 34, so as toreduce carryover of liquid particles in the gas stream.

Separation of the liquid particles from the gas-liquid stream occursaccording to the principles and methods described in U.S. Pat. Nos.6,290,738; 7,473,291; and 8,075,654, which were incorporated byreference herein above, and will therefore not be described furtherherein.

According to the present disclosure, the gas-liquid separator 10 furthercomprises an impactor shroud 36 that extends from a perimeter 38 of theimpaction surface 30 and has a free end 40 that extends toward theimpactor nozzle structure 26. Thus, the impactor shroud 36 extendsgenerally along (parallel to) a longitudinal axis A running through thegas-liquid separator 10. The free end 40 of the impactor shroud 36surrounds an outer surface 42 of the impactor nozzle structure 26. Inthe embodiment shown, both the impactor nozzle structure 26 and theimpactor shroud 36 have a generally cylindrical shape, and a diameter ofthe impactor shroud 36 is larger than a diameter of the impactor nozzlestructure 26 so as to surround the outer surface 42 of the impactornozzle structure 26.

The impactor shroud 36 is supported by the housing 16 by a cylindricalprojection 86 extending from an upper inner surface 88 of the housing16, which cylindrical projection 86 is in turn connected to a conicalportion 90, which is in turn connected to the impactor shroud 36.Alternatively, the impactor shroud 36 could be supported by the housing16 by a stilt structure 82 (FIG. 17) or a stilt structure 82″ (FIG. 20).In the embodiments shown, the impactor nozzle structure 26 comprises acylindrical chimney 54 connected to a circular nozzle plate 31; however,it should be understood that the impactor nozzle structure 26 could takemany other forms, such as a single integrated part.

Often times, high velocities within the housing 16 will causere-entrainment of liquid particles that have been flung to an innersurface 80 of the housing 16. In other words, instead of draining fromthe housing 16 as described in the patents incorporated by referencehereinabove, the liquid particles that have been flung to the innersurface 80 of the housing 16 are caught in the high velocity flow of gaswithin the housing 16 and re-entrained into the gas flow. This reducesthe efficiency of the gas-liquid separator 10, as liquid particles thathave already been separated by impaction are carried over into the gasflow exiting at the outlet 22. Therefore, the present disclosuredescribes several embodiments of baffles 8 a-8 k that can be used tominimize or alleviate liquid carryover due to re-entrainment. FIGS. 2-12show a variety of embodiments of baffles according to the presentdisclosure. The embodiments shown in FIGS. 2-4 normalize the flow of thegas stream (shown by arrows 34) as the gas stream exits the impactorshroud 36. The embodiments shown in FIGS. 5-12 cause the flow of the gasstream (shown by arrows 34) to spiral as the gas stream exits theimpactor shroud 36. All embodiments reduce carryover of liquid particlesin the gas stream as compared to an embodiment without baffle(s).

In the embodiments shown in FIGS. 2-4, the baffle normalizes the flow ofthe gas stream shown by arrows 34 as the gas stream exits the impactorshroud 36. Each of the embodiments of FIGS. 2-4 provides flow uniformityof the gas stream as shown by arrows 34 as it exits the shroud 36. Eachof these embodiments allows the radially outwardly expanding jet flow ofthe gas stream (shown by the arrows 34) to diffuse and distribute over awider flow area as it exits the shroud 36, to thereby reduce the jettingeffect as the gas stream bends around the impactor shroud 36.

In both of the embodiments of FIGS. 2 and 3, the baffles 8 a, 8 b extendfrom the free end 40 of the impactor shroud 36. Further, the baffles 8a, 8 b surround an outer surface 42 of the impactor nozzle structure 26.The baffles 8 a, 8 b also extend parallel to the outer surface 42 of theimpactor nozzle structure 26. More specifically, the baffles 8 a, 8 bextend parallel to the axis A and parallel to the outer surface of thechimney 54. In the embodiment of FIG. 2, the baffle 8 a comprises a meshscreen 44. The mesh screen 44 extends along the circumference of thefree end 40 of the impactor shroud 36. In one example, the mesh screen44 is designed such that its parameters produce a pressure dropcoefficient of close to one. The pressure drop coefficient is adjustablebased on the flow area of the mesh screen 44, and the permeability,porosity, etc. of the mesh screen 44. A perforated plate couldalternatively be used instead of a mesh screen 44 to achieve the sameobjective. In the embodiment of FIG. 3, the baffle 8 b comprises a pieceof reticulated foam 46. The reticulated foam 46 extends along thecircumference of the free end 40 of the impactor shroud 36.

In the embodiment of FIG. 4, the gas-liquid separator 10 furthercomprises a plurality of baffles 8 c comprising axially-extending ribs55 that radiate from an outer surface 48 of the impactor shroud 36. Theribs 55 extend co-axially with respect to the axis A running through theimpactor shroud 36, and also radiate from axis A. In one embodiment theribs 55 radiate from axis A at regular intervals, such as for example,shown by gaps 50 between each rib 55. In one example, the gaps 50between each rib 55 could be less than or equal to 5 mm in order to slowand normalize the jetting flow of the gas stream (shown by the arrows34) as it exits the impactor shroud 36. It should be understood that theribs 55 need not be spaced at regular intervals in order to achieve theobjective of the present disclosure.

Now referring to FIGS. 5-12, the embodiments shown therein comprise aplurality of baffles that cause the flow of the gas stream (shown byarrows 34) to spiral as the gas stream exits the impactor shroud 36.

In the embodiments of FIGS. 5-8, the plurality of baffles 8 d-8 gproject sideways (i.e., perpendicularly with respect to axis A) from asurface of the impactor shroud 36. As shown in FIG. 5, in oneembodiment, the plurality of baffles 8 d extend from an outer surface 48of the impactor shroud 36. In the embodiment shown, the plurality ofbaffles 8 d comprise ribs 56 that extend helically with respect to theouter surface 48 of the impactor shroud 36. For example, the ribs 56extend at an angle ω₁, ω₂ with respect to the axis A. This angle ω₁, ω₂may increase from the base 35 of the rib 56 to the tip 37 of the rib, asshown in the embodiment herein. In other words, the rib 56 may curvesuch that ω₁, measured at the base 35, is less than ω₂, measured at thetip 37. Alternatively this angle may remain the same as measured alongthe rib 56 from its base 35 to its tip 37, i.e. ω₁=ω₂.

In the embodiments of FIGS. 6-8, the plurality of baffles 8 e, 9 f, 8 gextend from an inner surface 58 of the impactor shroud 36. In theembodiments of FIGS. 6 and 7, the plurality of baffles comprise ribs 60that extend helically with respect to the inner surface 58 of theimpactor shroud 36. As can be understood from a comparison of FIGS. 6and 7, the ribs 60 may extend all the way from an underside 52 of theshroud 36 to the free end 40 of the shroud 36 (FIG. 7), or the ribs 60may extend front the underside 52 of the shroud 36 to a point short ofthe free end 40 of the shroud 36 (FIG. 6). From further comparison ofFIGS. 6 and 7, it can be seen that the ribs 60 can extend at differentangles α, β, θ, with respect to the axis A running through the impactorshroud 36. As described hereinabove with respect to the angles ω₁ and ω₂in FIG. 5, the angles may vary from the bases 39 of the ribs 60 to thetips 41 of the ribs 60 (compare angle β with angle θ in FIG. 7).Alternatively, the angles α, β may remain the same along the ribs 60from bases 39 to tips 41, i.e. β=θ in FIG. 7.

As shown in FIG. 8, the plurality of baffles 8 g can comprise fins 62that project radially inwardly from the inner surface 58 of the impactorshroud 36, i.e., towards the axis A. Although the fins 62 shown in FIG.8 do not extend in the direction of axis A to the free end 40 of theimpactor shroud 36, it is to be understood that the size/length of thefins 62 could vary from that shown herein. In the embodiment shown, thefins 62 each curve such that free ends 64 of the fins 62 curve into theimpactor shroud 36.

Alternatively, as shown in FIGS. 9-11, the plurality of baffles 8 h-8 jcomprise a plurality of fins 66 projecting from an underside 52 of theimpactor shroud 36 toward the impactor nozzle structure 26, i.e.,projecting in the direction of axis A. In the embodiment of FIG. 9, theplurality of fins 66 spiral out from the perimeter 38 of the impactionsurface 30. Each fin 66 in the plurality of fins has an inner edge 68and an outer edge 70. In the embodiment shown, an outer edge 70 of agiven fin overlaps an inner edge 68 of a fin adjacent to the given fin.For example, the fin 66″ has an outer edge 70″ that overlaps the inneredge 68′ of an adjacent fin 66′.

The fins 66 shown in FIGS. 10 and 11 vary in shape from those shown inFIG. 9 but the description herein above regarding the fins 66 appliesequally. In the embodiment of FIG. 10, the fins 66 project furtherradially outwardly from the perimeter 38 of the impaction surface 30than in the embodiment of FIG. 9. In the embodiment of FIG. 11, the fins66 project radially, but are squared off partway towards their outeredges 70. Further, the overlap between the outer edge 70 of one fin andthe inner edge 68 of an adjacent fin as shown in FIG. 11 is greater thanthe overlap shown in FIG. 9 or 10.

Alternatively, in the embodiment of FIG. 12, the impactor nozzlestructure 26 comprises a chimney 54 and the plurality of baffles 8 kproject from an outer surface of the chimney 54. In the embodimentshown, the plurality of baffles 8 k comprise ribs 72 that extendhelically with respect to the outer surface of the chimney 54, i.e. atan angle τ with respect to the axis A. It should be understood that theangle at which these ribs 72 extend with respect to the axis A extendingthrough the chimney 54 could vary.

Now with reference to FIGS. 13-16, the spiraling effect of the baffles 8d-8 k on flow in the gas-liquid separator 10 will be described. FIG. 13shows a gas-liquid separator 10 and the flow therein (simulated byparticle velocity lines) when no baffles are provided. The gas-liquidstream is shown entering through the chimney 54 at arrow 94. Thegas-liquid stream hits the impaction surface 30, which causes separationof liquid particles from the gas-liquid stream. The resulting gas streambends around the free end 40 of the impactor shroud 36, as shown byarrow 96, and exits at the outlet 22, as shown by arrow 96′. Because nobaffles are provided in the embodiment of FIG. 13, the gas stream doesnot spiral and therefore exhibits somewhat random motion, shown by arrow96″, before it exits through outlet 2. In contrast, as shown in FIG. 14,after hitting the impaction surface 30, the gas stream exiting from theshroud 36 (shown by arrow 96) is caused to spiral as shown by arrows 74.Such spiraling of the gas stream is caused by a plurality of baffles(not shown) comprising radial ribs or fins on the impactor shroud 36(see FIGS. 5-11) or on the chimney 54 (see FIG. 12). The flow continuesto spiral throughout the housing 16 (as shown by arrows 74) until itexits at outlet 22, as shown by arrow 96′.

FIGS. 15 and 16 illustrate the effect of such spiraling flow on theliquid particle content of the flow exiting at the outlet 22. While theparticle velocity lines shown in FIGS. 13 and 14 illustrate the flow ofthe gas or gas-liquid stream, the lines in FIGS. 15 and 16 approximatethe amount of liquid particles entrained in the gas or gas-liquidstream. FIG. 15 corresponds to FIG. 13 in that no baffles are providedand therefore no spiraling flow is provided. Although liquid particleshave been separated from the gas-liquid stream by hitting the impactionsurface 30, liquid particles are subsequently re-entrained into the gasstream. This is because the gas stream shown bending around the free end40 of the impactor shroud 36 exhibits high velocity jetting and contactsthe inner surface 80 of the housing 16 as shown by arrows 100. At theinner surface 80 of the housing, liquid particles that have collectedare re-entrained into the high-velocity gas stream. As such, many liquidparticles are shown exiting at the outlet 22.

In contrast, FIG. 16 corresponds to FIG. 14 in that spiraling flow isprovided by a plurality of baffles as shown and described above withrespect to FIGS. 5-12. Due to the spiraling flow caused by the baffles,any liquid particles that may have been re-entrained in the gas streamare flung to the inner surface 80 of the housing 16 by centrifugalforce, as shown by arrows 76. This flinging removes any liquid particlesthat may have been re-entrained after hitting the impaction surface 30.The flung liquid particles inertially collect on the inner surface 80 ofthe housing 16. The liquid particles then coalesce on the inner surface80 of the housing 16 and drain downwards by gravity.

The baffles 8 d-8 k, such as ribs and fins shown in FIGS. 5-12, can bedesigned to optimize spiraling flow to create more effective separationof liquid particles from the gas-liquid stream. For example, the exitangle α or β at the bases 39 of the ribs 60 (as shown in FIGS. 6 and 7)could be designed to be between 30-70°. Depending on the capability ofthe manufacturer to create such angles and the need for post-separatingcyclonic flow, these angles could be varied. An entrance angle θ at thetips 41 of the ribs 60 (see FIG. 7) could also be designed to enhancethe swirling flow. Each of the embodiments mitigates re-entrainment ofliquid particles via swirling flow by creating a post-separation cyclonewith ribs or fins.

Now turning to FIGS. 17 and 18, further embodiments of a gas-liquidseparator 10 of the present disclosure will be described. In theseembodiments, the gas-liquid separator 10 further comprises a ring 78,78′ projecting radially inwardly from an inner circumferential surface80 of the housing 16 downstream of the plurality of baffles 8. It is tobe understood that the baffle(s) could comprise any of the baffles 8 a-8k shown in FIGS. 2-12. In the embodiment shown in FIG. 17, the ring 78is attached to the impactor shroud 36 by a stilt structure 82. The stiltstructure 82 comprises a plurality of lower stilts 83 and a plurality ofupper stilts 85. In one embodiment, the lower stilts 83 are connected tothe shroud 36 at regular intervals around a circumference the shroud 36,while the upper stilts 85 are connected to the inner surface 80 of thehousing 16 at regular intervals around a circumference of the innersurface 80 of the housing 16. The stilt structure 82 allows for flowtherethrough via gaps 84 between each of the upper stilts 85 and each ofthe lower stilts 83. The stilt structure 82 holds the impactor shroud 36in place within the housing 16.

In contrast, in FIG. 18, the impactor shroud 36 is held within thehousing 16 by a cylindrical projection 86 extending from an upper innersurface 88 of the housing 16. The projection 86 is coupled to a conicalportion 90, which is coupled to the impactor shroud 36. Although theconical portion 90 is shown integrally molded to the impactor shroud 36,the parts could be connected in various other ways. Similarly, althoughthe conical portion 90 is shown connected to the cylindrical portion 86by a threaded connection, the parts could be connected in various otherways. The ring 78′ is coupled to the impactor shroud 36 by a stiltstructure 82′ having gaps 84′ that allow for how therethrough. The stiltstructure 82′ comprises a truncated cone, one end 87 of which has asmaller diameter and is coupled to the shroud 36, and the other end 89of which has a larger diameter and is coupled to the circumference ofthe inner surface 80 of the housing 16.

The ring 78, 78′, known as a “vortex finder ring”, ensures that largerre-entrained liquid particles are caught on the ring 78, 78′ and do notexit via the outlet 22. The effect of the ring 78, 78′ is shown in FIG.19, which shows an approximation of the amount of liquid particles inthe flow through the housing 16. After exiting the free end 40 of theimpactor shroud 36, the spiraling flow shown by arrow 74 is stopped bythe ring 78, which causes liquid particles to be flung to the innersurface 80 of the housing 16, thereby reducing the number of liquidparticles exiting at the outlet 22. Liquid particles that are caught onthe ring 78 are collected on the inner surface 80 of the housing 16 anddrain downward by gravity. Although FIG. 19 shows the ring 78 accordingto the embodiment of FIG. 17, it should be understood that the ring 78′of FIG. 18 also causes the swirling flow to stop, thereby causing liquidparticles to be flung to the inner surface 80 of the housing 16.

In another embodiment, as shown in FIG. 20, the gas-liquid separator 10comprises an outlet shroud 92 extending axially inwardly (i.e., into thehousing along axis A) from the upper inner surface 88 of the housing 16downstream of the plurality of baffles 8. In the embodiment shown, theoutlet shroud 92 comprises an axially projecting cylindrical tube thatextends perpendicularly with respect to the tube comprising the outlet22 of the gas-liquid separator 10. As shown in FIG. 21, whichapproximates the amount of liquid particles in the flow through thehousing 16, liquid particles collect along the inner surface 80 of thehousing 16 as shown by arrows 98 and the gas stream proceeds through theoutlet shroud 92 with fewer liquid particles than would otherwise beentrained were there no outlet shroud 92. This is because the alignmentof the outlet shroud 92 (i.e., the outlet shroud 92 being axiallyaligned with flow through the housing 16) causes cyclonic flow withinthe housing 16, which flings particles to the inner surface 80 of thehousing 16.

Disclosed herein is a shroud 36 for an inertial impactor gas-liquidseparator 10 that separates liquid particles from a gas-liquid stream byacceleration of the gas-liquid stream through a nozzle, such asorifice(s) 28, and towards an impaction surface 30 so as to produce agas stream. The shroud 36 is configured to extend from a perimeter 38 ofthe impaction surface 30 and has a free end 40 that extends toward thenozzle, such as orifice(s) 28. In some embodiments, the shroud 36comprises a plurality of baffles 8 d-8 k that cause the gas stream tospiral as the gas stream exits the shroud 36, such as shown in FIGS.5-12. In some embodiments, the plurality of baffles 8 d-8 g projectsideways from a surface of the shroud 36, such as is shown in FIGS. 5-8.

In one embodiment, such as shown in FIG. 5, the plurality of baffles 8 dproject from an outer surface 48 of the shroud 36. The plurality ofbaffles 8 d comprise ribs 56 that extend helically with respect to theouter surface 48 of the shroud 36.

In the embodiments shown in FIGS. 6-8, the plurality of baffles 8 e-8 gproject from an inner surface 58 of the shroud 36. As shown in FIGS. 6and 7, the plurality of baffles 8 e, 8 f comprise ribs 60 that extendhelically with respect to the inner surface 58 of the shroud 36. In theembodiment shown in FIG. 8, the plurality of baffles 8 g comprise fins62 that project radially inwardly from the inner surface 58 of theshroud 36. The fins 62 curve such that free ends 64 of the fins 62 curveinto the shroud 36.

As shown in FIGS. 9-11, the plurality of baffles 8 h-8 j can comprise aplurality of fins 66 projecting from an underside 52 of the shroud 36.The plurality of fins 66 spiral out from the perimeter 38 of theimpaction surface 30. Each fin 66 in the plurality of fins has an inneredge 68 and an outer edge 70, wherein an outer edge 70 of a given finoverlaps an inner edge 68 of a fin adjacent the given fin.

Now referring to FIG. 22, the present disclosure also includes a methodfor separating liquid particles from a gas-liquid stream. The methodcomprises receiving a gas-liquid stream through an inlet 18 of a housing16, as shown at box 201. The method includes accelerating the gas-liquidstream through a nozzle, such as orifice(s) 28, and at an impactionsurface 30, causing separation of liquid particles from the gas-liquidstream so as to produce a gas stream, as shown at box 202. The methodincludes directing a flow of the gas stream around an impactor shroud 36extending from a perimeter 38 of the impaction surface 30 and having afree end 40 extending towards the nozzle, such as orifice(s) 28, asshown at box 203. The method includes modifying a flow of the gas streamwith a baffle 8 a-8 k so as to reduce carryover of liquid particles inthe gas stream, as shown at box 204. The method includes discharging thegas stream through an outlet 22 of the housing 16, as shown at box 205.

The method may further comprise normalizing the flow of the gas streamas the gas stream exits the impactor shroud 36. This accomplished by wayof the apparatuses shown in the embodiments of FIGS. 2-4. For example,the method may include passing the gas stream through a mesh screen 44coupled to the free end 40 of the impactor shroud 36 so as to normalizethe flow of the gas stream. The method may alternatively comprisepassing the gas stream through a piece of reticulated foam 46 coupled tothe free end 40 of the impactor shroud. 36 so as to normalize the flowof the gas stream. The. method may alternatively comprise passing thegas stream through small gaps SO between baffles 8 c comprisingaxially-extending ribs 55 that radiate from an outer surface 48 of theimpactor shroud 36.

In alternative embodiments, the method may further comprise causing theflow of the gas stream 34 to spiral as the gas stream exits the impactorshroud 36. This is shown in the embodiments of FIGS. 5-12. In oneexample shown in FIG. 5, the method further comprises directing the gasstream through a plurality of baffles 8 d comprising ribs 56 that extendhelically with respect to an outer surface 48 of the impactor shroud 36.As shown in FIGS. 6 and 7, the method may further comprise directing thegas stream through a plurality of baffles 8 e, 8 f comprising ribs 60that extend helically with respect to an inner surface 58 of theimpactor shroud 36. As shown in FIG. 8, the method may further comprisedirecting the gas stream through a plurality of baffles 8 g comprisingfins 62 that extend radially inwardly from an inner surface 58 of theimpactor shroud 36. As shown in FIGS. 9-11, the method may furthercomprise directing the gas stream through a plurality of baffles 8 b, 8i, 8 j comprising fins 66 projecting from an underside 52 of theimpactor shroud 36 towards the impactor nozzle, such as orifice(s) 28.

In the above description certain terms have been used for brevity,clarity, and understanding. No unnecessary limitations are to beinferred therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes and are intended to be broadlyconstrued. The different apparatuses and methods described herein abovemay be used in alone or in combination with other apparatuses andmethods. Various equivalents, alternatives and modifications arepossible within the scope of the appended claims. Each limitation in theappended claims is intended to invoke interpretation under 35 U.S.C.§112(f), only if the terms “means for” or “step for” are explicitlyrecited in the respective limitation. While each of the method claimsincludes a specific series of steps for accomplishing the method, thescope of this disclosure is not intended to be bound by the literalorder or literal content of steps described herein, and non-substantialdifferences or changes still fall within the scope of the disclosure.

1-25. (canceled)
 26. A shroud for an inertial impactor gas-liquidseparator that separates liquid particles from a gas-liquid stream byacceleration of the gas-liquid stream through a nozzle and towards animpaction surface so as to produce a gas stream, the shroud configuredto extend from a perimeter of the impaction surface and having a freeend that extends towards the nozzle, the shroud comprising a pluralityof baffles that cause the gas stream to spiral as the gas stream exitsthe shroud.
 27. The shroud of claim 26, wherein the plurality of bafflesproject sideways from a surface of the shroud.
 28. The shroud of claim27, wherein the plurality of baffles project from an outer surface ofthe shroud.
 29. The shroud of claim 28, wherein the plurality of bafflescomprise ribs that extend helically with respect to the outer surface ofthe shroud.
 30. The shroud of claim 26, wherein the plurality of bafflesproject from an inner surface of the shroud.
 31. The shroud of claim 30,wherein the plurality of baffles comprise fins that project radiallyinwardly from the inner surface of the shroud.
 32. The shroud of claim31, wherein the fins curve such that free ends of the fins curve intothe shroud.
 33. The shroud of claim 30, wherein the plurality of bafflescomprise ribs that extend helically with respect to the inner surface ofthe shroud.
 34. The shroud of claim 26, wherein the plurality of bafflescomprise a plurality of fins projecting from an underside of the shroud.35. The shroud of claim 34, wherein the plurality of fins spiral outfrom the perimeter of the impaction surface.
 36. The shroud of claim 35,wherein each fin in the plurality of fins has an inner edge and an outeredge, and wherein an outer edge of a given fin overlaps an inner edge ofa fin adjacent to the given fin.
 37. A method for separating liquidparticles from a gas-liquid stream, the method comprising: receiving agas-liquid stream through an inlet of a housing; accelerating thegas-liquid stream through a nozzle and at an impaction surface, causingseparation of liquid particles from the gas-liquid stream so as toproduce a gas stream; directing a flow of the gas stream around animpactor shroud extending from a perimeter of the impaction surface andhaving a free end extending towards the nozzle; modifying a flow of thegas stream with a baffle so as to reduce carryover of liquid particlesin the gas stream; and discharging the gas stream through an outlet ofthe housing.
 38. The method of claim 37, further comprising normalizingthe flow of the gas stream as the gas stream exits the impactor shroud.39. The method of claim 38, further comprising passing the gas streamthrough a mesh screen coupled to the free end of the impactor shroud soas to normalize the flow of the gas stream.
 40. The method of claim 38,further comprising passing the gas stream through a piece of reticulatedfoam coupled to the free end of the impactor shroud so as to normalizethe flow of the gas stream.
 41. The method of claim 37, furthercomprising causing the flow of the gas stream to spiral as the gasstream exits the impactor shroud.
 42. The method of claim 41 furthercomprising directing the gas stream through a plurality of bafflescomprising ribs that extend helically with respect to an outer surfaceof the impactor shroud.
 43. The method of claim 41, further comprisingdirecting the gas stream through a plurality of baffles comprising finsthat project radially inwardly from an inner surface of the impactorshroud.
 44. The method of claim 41, further comprising directing the gasstream through a plurality of baffles comprising ribs that extendhelically with respect to an inner surface of the impactor shroud. 45.The method of claim 41, further comprising directing the gas streamthrough a plurality of baffles comprising fins projecting from anunderside of the impactor shroud towards the impactor nozzle structure.